<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="./css/inputnumber.css" />
    <link rel="stylesheet" href="./css/index.css" />
    <title>购物车</title>
  </head>
  <body>
    <div class="app-container" id="app">
      <!-- 顶部banner -->
      <div class="banner-box">
        <img src="./img/fruit.jpg" alt="" />
      </div>
      <!-- 面包屑 -->
      <div class="breadcrumb">
        <span>🏠</span>
        /
        <span>购物车</span>
      </div>
      <!-- 购物车主体 -->
      <div class="main" v-if="fruitList.length > 0">
        <div class="table">
          <!-- 头部 -->
          <div class="thead">
            <div class="tr">
              <div class="th">选中</div>
              <div class="th th-pic">图片</div>
              <div class="th">单价</div>
              <div class="th num-th">个数</div>
              <div class="th">小计</div>
              <div class="th">操作</div>
            </div>
          </div>
          <!-- 身体 -->
          <div class="tbody">
            <div
              class="tr"
              v-for="(item,index) in fruitList"
              :key="item.id"
              :class="{active:item.isChecked}"
            >
              <div class="td">
                <input type="checkbox" v-model="item.isChecked" />
              </div>
              <div class="td"><img :src="item.icon" alt="" /></div>
              <div class="td">{{ item.price }}</div>
              <div class="td">
                <div class="my-input-number">
                  <!-- disabled：禁用 -->
                  <!-- 一. -->
                  <button
                    :disabled="item.num <= 1"
                    class="decrease"
                    @click="item.num--"
                  >
                    -
                  </button>
                  <span class="my-input__inner">{{ item.num }}</span>
                  <button class="increase" @click="item.num++">+</button>
                </div>
                <!-- 二. -->
                <!-- <div class="my-input-number">
                  <button class="decrease" @click="desc(item.id)">-</button>
                  <span class="my-input__inner">{{ item.num }}</span>
                  <button class="increase" @click="add(item.id)">+</button>
                </div> -->
              </div>
              <div class="td">{{ item.num * item.price}}</div>
              <div class="td"><button @click="del(item.id)">删除</button></div>
            </div>
          </div>
        </div>
        <!-- 底部 -->
        <div class="bottom">
          <!-- 全选 -->
          <label class="check-all">
            <!-- 1.计算属性 -->
            <input type="checkbox" v-model="isAll" />
            <!-- 2.方法 -->
            <!-- <input type="checkbox" @click="All()" /> -->
            全选
          </label>
          <div class="right-box">
            <!-- 所有商品总价 -->
            <span class="price-box">
              总价&nbsp;&nbsp;:&nbsp;&nbsp;¥&nbsp;
              <span class="price">{{ totalPrice }}</span>
            </span>
            <!-- 结算按钮 -->
            <button class="pay">结算( {{ totalNum }} )</button>
          </div>
        </div>
      </div>
      <!-- 空车 -->
      <div class="empty" v-else>🛒空空如也</div>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <script>
      const defaultList = [
            {
              id: 1,
              icon: "./img/火龙果.png",
              isChecked: true,
              num: 2,
              price: 6,
            },
            {
              id: 2,
              icon: "./img/荔枝.png",
              isChecked: false,
              num: 7,
              price: 20,
            },
            {
              id: 3,
              icon: "./img/榴莲.png",
              isChecked: false,
              num: 3,
              price: 40,
            },
            {
              id: 4,
              icon: "./img/鸭梨.png",
              isChecked: true,
              num: 10,
              price: 3,
            },
            {
              id: 5,
              icon: "./img/樱桃.png",
              isChecked: false,
              num: 20,
              price: 34,
            },
          ]
      const app = new Vue({
        el: "#app",
        data: {
          // 水果列表
          fruitList: JSON.parse(localStorage.getItem('fruitList')) || defaultList,
        },
        methods: {
          // 删除
          del(id) {
            this.fruitList = this.fruitList.filter((item) => item.id !== id);
          },

          // 减
          // desc(id) {
          //   const fruitList = this.fruitList.find((item) => item.id === id);
          //   fruitList.num--;
          // },
          // // 加
          // add(id) {
          //   const fruitList = this.fruitList.find((item) => item.id === id);
          //   fruitList.num++;
          // },
          // 全选（方法一）
          //函数名和变量名不能相同
          // All() {
          //   this.isAll = !this.isAll;
          //   this.fruitList.forEach((e) => (e.isChecked = this.isAll));
          // },
        },
        computed: {
          // 全选（方法二）
          isAll: {
            get() {
              return this.fruitList.every((item) => item.isChecked);
            },
            set(value) {
              this.fruitList.forEach((item) => (item.isChecked = value));
            },
          },

          // 总价
          // totalPrice() {
          //   return this.fruitList.reduce((sum, item) => {
          //     if (item.isChecked) {
          //       return sum + item.num * item.price;
          //     } else {
          //       return sum;
          //     }
          //   }, 0);
          // },
          // // 选中总数
          // totalNum() {
          //   return this.fruitList.reduce((sum, item) => {
          //     if (item.isChecked) {
          //       return sum + item.num;
          //     } else {
          //       return sum;
          //     }
          //   }, 0);
          // },

          // 过滤出选中的列表（做缓存）
          checkedList() {
            return this.fruitList.filter((item) => item.isChecked);
          },
          // 统计选中的总价
          totalPrice(){
            return this.checkedList.reduce((sum,item)=>sum + item.num *item.price,0)   //累加价格
          },
          // 统计选中的总数
          totalNum(){
            return this.checkedList.reduce((sum,item)=> sum + item.num,0)  //累加数量
          }


        },
        // 侦听器 数据变化，执行业务/发送异步请求
        watch: {
          fruitList:{
            handler(){
              localStorage.setItem('fruitList',JSON.stringify(this.fruitList))
            },
            deep:true
          }

        },
      });
    </script>
  </body>
</html>
